   .     my_script  -
 TEMPDIR,  -/temp:

$ TEMPDIR=~/temp my script

 TEMPDIR    ,   
 my_script.   ,    ,  -
  ,     ,   .

 bash         .

   

  (shell script)   ,  ,  
 .        ,
       . ,   -
     Linux,    
,    .     ,  
         
          (.  "-
"  7).         -
    .

   ,     ,  
      (
  ).      
      ,     -
     .  -
    " "  28.

    ,      
.           -
.           -
    .

chmod:    

   ,      ,  -
       ,   (. -
 " "  6).       , 
,         ; 
 ,     .

          
    .    
 whoson,       :

$ cat whoson

date

echo ,   

who

$ whoson
bash: ./whoson: Permission denied     (  )

 9.  II: Bourne Again Shell 283